Abstract: In accordance with the fact that the external of return method of in vestment has not universally been used yet to evaluate the engineering projects in our economic researches, the paper expounds the calculating method and its practicability in engineering investment projects, analyses and compares advantages and disadvantages between the external rate of return and the internal rate of return, and puts forward a proposal that the external rate of return of investment serve as one of the main evaluation methods of technical economy.

Key words: External rate of return of investment, nternal rate of return of investment, et present worth